The prognosis varies; the acute and nervous forms are usually fatal. But when the disease develops slowly, recovery may occur.
Pathogeny. Practical observation and laboratory researches show that the above conditions result from poisoning. Histological examination of livers from sheep which have died rapidly shows complete degeneration of the hepatic cells, which become incapable of performing their function. The biliary acids, no longer being withdrawn from the circulating blood, produce general intoxication, destruction of the blood corpuscles, and the appearance of hæmaphæic icterus and hæmoglobinuria.
Treatment. Being convinced that acidity alone caused this disease, the older practitioners suggested the administration of salines. In reality it is necessary to check fermentation. Drainage of the silos in which beet pulp is stored is often sufficient for this purpose; but if badly arranged, drainage rather assists the growth of moulds and various organisms in the mass, which affords a medium favourable to their multiplication. Complete desiccation would undoubtedly give much better results, but cannot economically be effected. The best practical measure consists in storing the pulp in special silos, divided into compartments by lattice work partitions. The escape of liquid is facilitated by forming the floors of the silo with a sufficient slope. Preservation, however, is not perfect, and some compartments are always found damaged. Excessive fermentation can be checked by adding ordinary salt to the pulp in the proportion of ·2 per cent.
Curative treatment comprises restricted diet for several days, and the administration of milk, carbonate of soda, and stimulants, which favour excretion of the toxins. Some patients may be saved by subcutaneous injections of large quantities of normal salt solution. When poisoning is pronounced, and the viscera are clearly injured, it is more economical to slaughter the animals, provided that the icterus does not render the flesh useless for sale.
CHAPTER VIII.
PARASITES OF THE DIGESTIVE APPARATUS.
Parasites of the digestive apparatus are extremely common in ruminants, some, like the infusoria of the rumen, being of no importance, others, on the contrary, appearing to play a predominating part in the development of certain forms of anæmia and serious wasting diseases, such as the various forms of gastro-intestinal strongylosis, coccidial enteritis, etc.
GASTRO-INTESTINAL STRONGYLOSIS IN SHEEP.
PARASITIC GASTRO-ENTERITIS. OVINE PASTEURELLOSIS.
Verminous diseases of the abomasum are common in the sheep and goat, but (in France at least) appear rare in the ox.
Causation. Gastro-intestinal strongylosis is produced by various parasites of the genus Strongylus, such as Strongylus contortus, Strongylus convolutus, Strongylus instabilis, Strongylus circumcinctus, Strongylus filicolis, which occur not only in the abomasum, but also in the small portions of the first intestine, sometimes in very large numbers.